What velocity should I expect from the 16-inch barrel of my AR if I was using M193 issue ammo? I found a ballistics table for military ammo that gives the standard response of 3250 fps from I assume the 20-inch government barrel. How much is lost in that four inches that ain't there? Thanks.

Here are the results out of my 16" Bushy:

factory average SD high low spread shots

s&b 3103 38 3134 3051 83 5
Fed AE 3012 29 3046 2975 71 5
S&B 3129 25 3139 3114 25 5
S. af 3104 33 3122 3089 14 5
Fed AE 3035 116 3065 2949 44 6

OK. I see the average is just under 3100-- 3077 to be exact. I asked because I chrono'ed 20 rounds of that "mystery powder" I cobbled up from four or five powders we discussed (and some of us viciously dissed) over in the "Powder data needed" thread of a few days ago.

Here are the stats:

Mean: 2745
Standard Deviation: 44
Hi: 2821
Lo: 2679
Median: 2750
Average Absolute Deviation from Mean: 36.4
95% Confidence Interval for Actual Mean: 2724 through 2766

I ain't no stats genius, but I think this means: the average is 2745 fps; there are as many shots above 2750 fps as there are below 2750 fps and an SD of 44 equates to a ±1.6% variance in the 20 rounds from 2745 fps (I think that's pretty tight). I have no good understanding of the Confidence Interval or the Average Absolute Deviation Value. I hated stats in school and don't remember a damned thing from it. I took it in Fall 1984. As soon as I left the exam, I forgot everything I crammed for the final. I hated stats.

I asked the original question because I wanted to show by the figures I generated that my "mystery powder" was in no way ever going to be so dangerous that it would explode in a massive fireball that would wreak havoc far and wide, killing little children and little old ladies, along with cute puppies and fuzzy little kittens. You'd think the way some carried on about what I was doing, that I was some sort of evil monster bent upon world domination via the burning of an evil, unknown powder in an evil black rifle. Well, Antelope Sniper has provided information against which I can compare mine, and I see that my powder propelled the bullet at a speed approximately 330 fps SLOWER than commercial ammo. I have to assume the ammo Antelope Sniper used is commercial because I see no LC, WCC, TW or any other military head markings I recognize so listed. If my ammo is slower, can it not be assumed that the pressure is also lower? I did not load "reduced loads." The cases were filled to just under the shoulder. I loaded 23.3 grains of the hodge-podge powder, which was a large majority AA 2200 DP, into mixed mil-surp brass. No way its orientation in the case could result in poor or erratic ignition because the maximum load for AA 2200 is about 25 grains in the .223Remington.

What I am saying is: You who poo-pooed what I did are well within your rights to do it. This is a public forum; I expect disagreement. But I take my first-ever umbrage with they who say what I did was dumb, insane, ignorant, ill-informed, that "Houston has a problem," that I had to be kidding for doing what I did, that there is a reason lions eat their young, that what I did induced laughter in one individual such that he could hardly type, and that I should be banned from the Reloading Forum for my description as to how I'd generate a load for an unknown powder. Well, well. Aren't we all just so much smarter than that homebrewer guy? We weren't there but we know so much more, don't we?

I neither demanded nor suggested anyone proceed to replicate my experiment. I neither decried nor insulted anyone for voicing disapproval. I forced no one to sit by my bench at the range as I fired it. I forced no one to fire the ammo generated by a process that was so roundly ridiculed. I simply described what I was doing with a lot of unknown powder-- the MAJORITY of which I knew. What I wrote is there for you to take, leave, or just read for enjoyment or laughs. Now we have statistical results as to the performance of that powder compared to what I assume is commercial loadings-- and we see that my powder is tame stuff, indeed. I could probably go up another two or three grains, but that will not be necessary. The stuff shoots just under one MOA at 100 yards out of a homebuilt, stainless AR with a 40X scope and a 16-inch barrel, so why change it? I have enough powder to load up several hundred more. And I'll do it, too. I don't care what anybody says...

Sellier and Bellot M-193 Mil spe
Federal American Eagle
South African M-193 Mil-spec

The exact headstamp on the last was:
m1a4 042 d96

Having experiment with less then standard powders in the past (kids, if you don't know what you are doing, don't try this at home) I'd say your powder has a burn rate similar to H380. Of course that's just kind of a guestimate. Changes are you could work up to something in the 2900-3000 fps range without much problem. Once you start pushing above 3000 fps with a 52-55gr bullet the 16" barrels, things start getting more interesting, and you need to be more careful. Of course powders can exibit different characteristics in different calibers, so keep that in mind if you decide to adopt your new creation to a different caliber.

I shoot mostly .223, Antelope. Whatever this crap is it ain't meant for large-case rounds, being mostly fast-burning AA 2200DP. The only other rifle for which I reload is a 300WSM; I'll never shoot this witch's brew in it. I have plenty of H4831SC and RL-22 for that gun. I have a white jug of what I was told is H-380, but I think it's really H-414. That is also a good large-case powder. Looks like I get another opportunity to experiment with an unknown powder. Life can be interesting now and then...

Ve locity variation in different rifles of the same make and model

You might find the above of interest

Now that is interesting. Both the gun and the
ammo may be "fast", but not really with each other. One more idea to think about.
Good Luck!

Homebrewer

Have you tested for accuracy yet?

quote:

Originally posted by wistrapper:
Homebrewer

Have you tested for accuracy yet?

Yes. I shot ten of them a few weeks ago before I knew how fast it was. I shot a bunch yesterday after the chrono measurements. The stuff shoots inside a one-inch circle at 100 yards. I estimated a starting charge based on experience with the majority portion of the powder and went for it. It shoots well enough for me that further screwing with it is unnecessary.

I have loaded all of the mystery powder into .223 cases and used 55-grain FMJ bullets. I got just a few over 400 rounds out of it. At a low estimate of $0.25 per round, that's a hundred bucks worth of ammo some seemed to say I should have thrown away. I'll shoot it at targets and jackrabbbits. It's good ammo-- just a little slower than factory rounds.